JP2007195861A - Shuttlecock - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shuttlecock which employs a base main body formed of foamed resin and thereby has homogeneous product physical properties and improved durability and uniform quality while keeping the same flight characteristics and ball hitting property as those of a shuttlecock using a base main body of a conventional natural cork. <P>SOLUTION: The shuttlecock is composed of: a skirt part 4 composed of feathers 3 (14 to 16 feathers) of a natural water bird, a land bird, or the like; and the nearly hemispherical base main body 2. The base main body 2 is integrally formed of foamed resin made of polyolefin-based resin. The base main body has a specific gravity of 0.16 to 0.22, and a compression displacement of 6 mm to 8 mm for 300 N load when a compression test is performed at 23°C. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a shuttlecock used in badminton competitions.

  As shown in FIG. 4, the shuttlecock 21 used in the badminton competition is provided with natural waterfowl and landfowl blades 23 (14 to 16) on the upper surface of a substantially hemispherical base body 22. In general, the ring is planted in a ring shape and the blade shaft 24 of each blade 23 is connected by a thread 25. In addition, although not shown in the figure, instead of using the natural waterfowl or landbird blade 23 as described above, the aerodynamic characteristics of the natural blade 23 are approximated by a synthetic resin such as nylon resin. There is also known a shuttlecock (so-called nylon sphere) in which a skirt portion formed in a skirt shape is formed and the skirt portion is planted on the upper surface of the base body 22.

  By the way, the performance required for the shuttlecock includes stability at the time of flight, in particular, the flight distance and the flight trajectory, and so on. The shuttlecock 21 used is the best, and is generally used widely including official games. At the same time, in order to obtain a good shot feeling and rebound when hitting, the base body 22 constituting the shuttlecock 21 is usually a natural cork covered with leather, or a foam such as PVC or polyurethane. Is used.

Japanese Patent Laid-Open No. 11-57096 JP 2003-284800 A

  However, in the conventional shuttlecock 21, if the base body 22 is made of natural cork, it is difficult to obtain a homogeneous one because the cork is naturally produced. In particular, natural cork has a large number of non-uniform pores inside, so the mass in each part is not uniform, and the center of gravity of the completed base body 22 is biased even if the cork is carefully selected and used. There is a problem that the flying direction of the struck shuttlecock 21 is not stable because the mass of each produced base body 22 is easily changed.

  The shuttlecock using natural cork for the hitting head has the problems that the natural material inevitably has a large variation in weight and the quality is not constant.

  In addition, in Patent Document 1 and Patent Document 2, although the conventional natural cork base body is disclosed as a shuttlecock having a feature that leaves its function, the specific gravity of conventional natural cork is the same, There is no technical disclosure or suggestion for obtaining a base body made of foamed resin having compressive strength.

  Therefore, the present invention solves the above-mentioned problems, and by making the base body of the shuttlecock made of foamed resin, the product physical properties are uniform, and the same flight characteristics and hitting performance as the shuttlecock which was the base body of the conventional natural cork It is an object of the present invention to provide a shuttlecock having improved durability and constant quality while maintaining the above.

  In order to achieve the above object, a shuttlecock according to claim 1 of the present invention is a shuttlecock in which a plurality of blades are annularly planted on the upper surface of a substantially hemispherical base body to form a skirt portion. The base body is made of a polyolefin-based resin, has a specific gravity of 0.16 to 0.22, and a compression displacement amount of 6 mm to 8 mm at a load of 300 N when a compression test is performed at 23 ° C. This is a shuttlecock characterized by that.

  A shuttlecock according to a second aspect of the present invention is the shuttlecock according to the first aspect, wherein the polyolefin resin is an ethylene-vinyl acetate copolymer resin (EVA) with respect to 80 to 90 parts by weight of polyethylene (PE). 5 to 20 parts by weight of a shuttlecock.

  A shuttlecock according to a third aspect of the present invention is the shuttlecock according to the first aspect, wherein the polyolefin resin is an ethylene-methacrylic acid copolymer (ionomer resin). is there.

  By adopting a base body made of polyolefin resin, compared to the case where the blade shaft is planted in natural cork, the planted part is less likely to loosen even by repeated striking, greatly improving the durability of the shuttlecock. To do. Moreover, there is almost no variation in mass and quality as in the case of using natural cork.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
FIG. 1 is a diagram illustrating the appearance of the shuttlecock 1 according to the first embodiment of the present invention, and FIG. 2 is a diagram illustrating the configuration of the base body 2.

  That is, as shown in FIGS. 1 to 2, the shuttlecock 1 of this embodiment includes a skirt portion 4 composed of blades 3 (14 to 16) such as natural waterfowl and land birds, and a substantially hemispherical shape. The base body 2 is integrally formed of a foamed resin made of polyolefin resin.

The specific gravity of the base body 2 of the present invention is set in the range of 0.16 to 0.22.
In addition, the base body made of the polyolefin resin foam when the compression tension test is performed at 23 ° C. is set so that the amount of compressive displacement at a load of 300 N is 6 mm or more and 8 mm or less.

  Therefore, by setting it as the set range, the base body formed of natural cork alone has substantially the same elasticity, and a good feel at impact similar to natural cork is obtained. For this reason, the deviation of the center of gravity of the base body 2a and the variation in mass can be eliminated, and stable flight characteristics can be obtained at the time of hitting.

  In addition, by adopting the polyolefin-based resin in the base body, the durability when hit with a racket is good, so that the conventional skin coating (synthetic leather urethane) of natural cork may be unnecessary it can.

  The polyolefin resin used in the present invention is particularly excellent in elongation of an ethylene resin, and the ethylene resin includes homopolymers and copolymers based on ethylene, such as polyethylene and ethylene. -Vinyl acetate copolymer (EVA), ethylene-propylene copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer (ionomer resin) and mixtures thereof.

  Examples of the polyethylene include, for example, random or block copolymers containing ethylene as a main component in addition to homotype polyethylene such as low density polyethylene, linear low density polyethylene, medium density polyethylene, and high density polyethylene. Examples of the ethylene-based copolymer include an ethylene-propylene copolymer, an ethylene-propylene-diene terpolymer, an ethylene-butene copolymer, an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid copolymer, Examples thereof include ethylene-acrylic acid ester copolymers.

  Among the polyolefin resins, those having a relatively low melting point such as low density polyethylene, cotton-like low density polyethylene, ethylene-vinyl acetate copolymer, etc. due to compatibility with ethylene-methacrylic acid copolymer (ionomer resin). Preferably used.

  Moreover, the ethylene-methacrylic acid copolymer (ionomer resin) used in the present invention is obtained by cross-linking the ethylene-methacrylic acid copolymer molecules with metal ions.

  A crosslinking agent and / or a crosslinking aid, a foaming agent, and various other additives as required can be added to these polyolefin resins in the base body 2 of the present invention.

  Any chemical foaming agent may be used as long as it is a decomposition type that generates a gas necessary for foaming by heating, such as azodicarboxamide, dinitrosopentamethylenediamine, sulfonyl hydragit, Examples include sodium bicarbonate and ammonium bicarbonate.

  If the amount of the pyrolytic foaming agent added is small, the foamable resin molded product may not foam, whereas if it is large, the foam of the crosslinked polyolefin resin foam may burst, the polyolefin resin 0.2-30 weight part is preferable with respect to 100 weight part, and 1-20 weight part is more preferable.

  In foaming, other additives can be optionally added. Examples of such additives include fatty acid amides, fatty acid metal salts, antioxidants, weathering stabilizers, light stabilizers, UV absorbers, pigments, dyes, plasticizers, lubricants, flame retardants, inorganic fillers, etc. It can be illustrated. Examples of the inorganic filler include silica, alumina, calcium carbonate, talc, clay, zeolite, carbon black, glass fiber and the like.

In the present invention, a polyfunctional monomer can also be used as a crosslinking aid.
Examples of the polyfunctional monomer include divinylbenzene, trimethylolpropane trimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol dimethacrylate, trimellitic acid triallyl ester, triallyl isocyanurate, and ethyl vinylbenzene. Can be used. These polyfunctional monomers can be used alone or in combination of two or more. These polyfunctional monomers are added in an amount of about 0.2 to 5 parts by weight with respect to 100 parts by weight of the resin matrix.

  A general-purpose method is used as a method of heating and foaming the polyolefin resin of the base body 2.

  For example, a polyolefin-based resin composition is molded using a general-purpose melt kneader such as an extruder, subjected to the crosslinking treatment described below as necessary, and then heated to a temperature higher than the foaming temperature of the foaming agent to cause foaming. In addition to the so-called “post-foaming method”, the foamable polyolefin resin composition is melt-kneaded with an extruder and heated to a temperature higher than the foaming temperature of the foaming agent to crosslink the resin component as necessary, and foamed simultaneously with extrusion. Let

  In the method for molding a shuttlecock according to the present invention, the polyolefin resin material is charged into a mold for molding a base body, and after mold clamping, heated at a predetermined temperature for a predetermined time to be foam-cured. Get the base body. Thereafter, natural blades (16 pieces) are planted in an annular shape on the upper surface of the base body, and the blade shafts of the respective blades are connected and fixed with a shaving thread to obtain the shuttlecock 1 of the present embodiment.

(Embodiment 2)
Next, a second embodiment of the present invention will be described with reference to FIGS.

  The shuttlecock 2 according to the second embodiment includes a skirt portion 4 composed of natural blades 3 and a substantially hemispherical base body 2, as in the shuttlecocks according to the first and second embodiments.

  The base body 2 is integrally formed of a polyolefin-based foamed resin in which polyethylene (PE) and ethylene-vinyl acetate copolymer resin (EVA) are blended.

  The blending ratio of the polyethylene (PE) and the ethylene-vinyl acetate copolymer resin (EVA) is 5 to 15 parts by weight of the ethylene-vinyl acetate copolymer resin (EVA) with respect to 80 to 90 parts by weight of the polyethylene (PE). A proportion is preferred. Although it is appropriately selected depending on the desired physical properties of the foam, in order to obtain excellent extrusion foam moldability, the ratio of the latter 8 to 12 parts by weight is preferable with respect to the former 80 to 90 parts by weight.

  In the base body 2, the polyethylene (PE) and the ethylene-vinyl acetate copolymer resin (EVA) are mixed with a crosslinking agent and / or a crosslinking aid, a foaming agent, and various other additives as required. An agent can be added.

  By setting the blending ratio, the base body 2 of the present invention has a specific gravity in the range of 0.16-0.22, and the polyolefin resin foamed when the compression tension test is performed at 23 ° C. The base body made of a body can have a compression displacement amount of 6 mm to 8 mm at a load of 300 N.

  Therefore, the base body formed of natural cork alone has substantially the same elasticity, and a good feel at impact similar to natural cork is obtained. For this reason, the deviation of the center of gravity of the base body 2 and the variation in mass can be eliminated, and stable flight characteristics can be obtained at the time of impact.

(Embodiment 3)
Next, Embodiment 3 of the present invention will be described with reference to FIGS.

  The shuttlecock 2 of the third embodiment is composed of a skirt portion 4 composed of natural blades 3 and a substantially hemispherical base body 2 in the same manner as the shuttlecocks of the first and second embodiments.

  The base body 2 is integrally formed of a foamed resin made of an ethylene-methacrylic acid copolymer (ionomer resin).

  A cross-linking agent and / or a cross-linking aid, a foaming agent, and various other additives as required may be added to the foamed resin comprising these ethylene-methacrylic acid copolymers (ionomer resins) in the base body 2. it can.

  By making the base body 2 made of an ethylene-methacrylic acid copolymer (ionomer resin), the base body 2 according to the present invention has a specific gravity in the range of 0.16-0.22, and at 23 ° C. The base body made of the polyolefin resin foam when the compression tension test is performed can have a compression displacement amount of 6 mm to 8 mm at a load of 300 N.

  Therefore, the base body formed of natural cork alone has substantially the same elasticity, and a good feel at impact similar to natural cork is obtained. For this reason, the deviation of the center of gravity of the base body 2 and the variation in mass can be eliminated, and stable flight characteristics can be obtained at the time of impact.

Example 1
Polyethylene (PE) foamed polyolefin resin obtained by mixing ethylene-vinyl acetate copolymer resin (EVA) at a ratio of 15 parts by weight with 90 parts by weight of polyethylene (PE) and adding a cross-linking agent and a foaming agent thereto. A resin material was prepared.

  The foamed resin material was put into a mold for molding the base body, and after clamping, heated at 160 ° C. for 20 minutes to be foamed and cured, thereby producing a base body having a specific gravity of 0.17.

(Example 2)
100 parts by weight of an ethylene-methacrylic acid copolymer (ionomer resin) (trade name: High Milan 1702 manufactured by Mitsui DuPont Polychemical Co., Ltd.), a polyolefin resin foamed resin material obtained by adding a crosslinking agent and a foaming agent to pellets. A base body having a specific gravity of 0.17 was produced in the same manner as in Example 1.

(Comparative Example 1)
As Comparative Example 1, a conventional commercial product was used. In this commercial product, the base body is entirely made of natural cork.

(Comparative Example 2)
Polyethylene (PE) foamed polyolefin resin obtained by mixing ethylene-vinyl acetate copolymer resin (EVA) at a ratio of 50 parts by weight with 50 parts by weight of polyethylene (PE) and adding a crosslinking agent and a foaming agent to this. A resin material was prepared, and a base body having a specific gravity of 0.17 was produced in the same manner as in Example 1.

(Comparative Example 3)
Polyethylene (PE) foamed polyolefin resin obtained by mixing ethylene-vinyl acetate copolymer resin (EVA) at a ratio of 30 parts by weight with 70 parts by weight of polyethylene (PE) and adding a crosslinking agent and a foaming agent to this. A resin material was prepared and a base body having a specific gravity of 0.17 was produced in the same manner as in Example 1.

The relationship between the compressive stress and displacement of the base bodies of Examples 1 and 2 and Comparative Examples 1 to 3 was subjected to a compression test using a compression tester, and the displacement and compressive stress were read from the obtained chart and shown in FIG.
FIG. 3 shows a compression load variation curve showing a difference in compression characteristics.

  In the compression test, a load cell having a maximum load of 500 N is used, and a compression jig is attached to the load cell to perform the compression test. The base body is set in close contact with the measuring device carrier, and the lower end of the pressing jig is in contact with the base body in the direction of the side surface 2a shown in FIG. 2, and the pressing jig is lowered at a speed of 1 mm / min. Compress the base body.

  As shown in FIG. 3, when comparing the compression characteristics of Example 1, Example 2 and Comparative Example 1, the amount of compressive displacement at a load of 300 N is 7.1 mm in Example 1, and Example 2 Was 7.4 mm, and Comparative Example 1 was 6.3 mm. Further, comparing Example 1, Example 2 and Comparative Example 1, it can be seen that an equivalent compression load variation curve is shown.

  Further, when compared with Comparative Example 1, Comparative Example 2 and Comparative Example 3 show different compression load variation curves.

  Therefore, the base bodies of Examples 1 and 2 have approximately the same elasticity as the base body formed of natural cork alone, and a good feel at impact similar to natural cork is obtained. For this reason, the deviation of the center of gravity of the base body 2 and the variation in mass can be eliminated, and stable flight characteristics can be obtained at the time of impact.

FIG. Structure explanatory drawing of a base body. Explanatory drawing which shows the compression load variation curve shown about the difference of a compression characteristic. External appearance explanatory drawing of the conventional shuttlecock.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shuttle cock 2 Base main body 2a Side surface 3 Blade | wing 4 Skirt part 21 Shuttle cock 22 Base main body 23 Blade | wing 24 Axle 25 Warp yarn

Claims (3)

  In a shuttlecock in which a plurality of blades are annularly implanted on the upper surface of a substantially hemispherical base body to form a skirt portion, the base body is made of a polyolefin resin and has a specific gravity of 0.16 to 0.00. 22 and a shuttlecock having a compression displacement amount of 6 mm to 8 mm at a load of 300 N when a compression test is performed at 23 ° C.   The shuttlecock according to claim 1, wherein the polyolefin resin is formed by blending 5 to 20 parts by weight of ethylene-vinyl acetate copolymer resin (EVA) with respect to 80 to 90 parts by weight of polyethylene (PE). . The shuttlecock according to claim 1, wherein the polyolefin resin is an ethylene-methacrylic acid copolymer (ionomer resin).

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